1. Technical Field of the Invention
This invention relates to a protection device for medical needles connected to a portion of tube, to prevent accidental pricking after using the needle. The field of application includes needles for infusion, for dialysis or plasmapheresis, for transfusions and for sampling.
2. Prior Art
Pricking by medical needles after their use on a patient represents a serious and widespread risk for personnel operating in the health sector.
To solve this problem protection devices are known comprising substantially a tubular casing coaxial to the tube to which the needle is connected, and having a hook-shaped front projection by which the device is retained by a finger of the hand which is pressed against the surface of the patient, at the point in which the needle is inserted into the patient""s body.
The needle is extracted from the patient""s body by pulling the tube rearwards; this operation causes the needle to withdraw while the protection device is held still by the finger, with the result that the needle slides under the projection and is retracted into the interior of the tubular casing, where its point is enclosed and protected against contact with external bodies.
As the device is applied to needles of the type having two fins positioned close to the rear end (butterfly needles), the tubular casing possesses two longitudinal slits in its lateral walls for passage of the fins.
An object of the present invention is to overcome those drawbacks of known devices, in particular with regard to the dangers involved in extracting the needle from the patient""s body. In this respect, this operation is delicate in itself, even without the protection device being present, because in many cases the needle point has a cutting edge and can damage the patient. The fact that the operator has to retain the protection device while at the same time making the extraction by gripping the tube at a point relatively far from the needle, makes the operation even more difficult and risky because of the danger of cutting the patient, in particular at the point of penetration of the needle.
Another drawback lies in the low rigidity of the tubular casing, particularly because of the presence of the longitudinal slits, and which in general means that it is impossible to ensure that the point of the needle is properly enclosed, secured and protected.
As stated, one object of the present invention is to overcome said drawbacks.
Another object is to provide a device which can be applied to the needle when this is already inserted into the patient""s body, just before the needle is to be extracted.
These and further objects are attained by the device of the invention as characterised in the claims.
The invention is based on the fact of comprising: a protection casing arranged to enclose and cover the needle after use, it being initially applied in a position to the rear of the point of the needle; a front end facing the point of the needle, to be rested against a foreign body for reaction in extracting the needle from the patient""s body; means for securing the device to the tube; and thrust means which when operated by the operator""s finger increase the distance between the securing means and said front end in order to cause the needle to move towards the protection casing until it lies inside the interior of this latter.
In particular, the device comprises a rear portion connected to the rear of the protection casing and carrying the means for securing the device, said front end being defined by the front end of the protection casing.
The protection casing is of such a shape as to enable it to vary its dimension in the longitudinal direction, said thrust means acting to produce an increase in the longitudinal dimension and consequently in the distance between the rear portion and the front end of the protection casing. In particular, the protection casing comprises initially diverging opposing lateral walls which can be made to approach each other to produce said increase in the distance between said rear portion and the front end of the protection casing.